Roller jacks.....

In the shop it's all steel for me,but I use the alum ones for my car trailer and keep one in my ramchgr,the alum one I use now which is the next size up from the smaller one [harbor freight] I put diff castors on I robbed from a old steel jack as the orig ones self destructed...I like the weight aspect of the alum ones but the quality needs to be improved upon as in the castors..but hey it's harbor freight dont expect a peach from an apple tree...lol...